Image processing apparatus, image processing method, and imaging apparatus

ABSTRACT

The present technique has a face detection unit configured to detect a face region which is determined as a face in an image, a position specifying unit configured to specify a particular position in the image, a range specifying unit configured to set a hue range which has a first range containing a hue at a position specified by the position specifying unit in a case where the position specified by the position specifying unit is not contained in the face region and to set a hue range which has a second range containing a hue at a position specified by the position specifying unit and wider than the first range in a case where the position specified by the position specifying unit contains the face region, and image processing unit for performing image conversion processing based on color information contained in the hue range.

RELATED APPLICATIONS

This application claim the benefit of Japanese Application No.2013-056344, filed on Mar. 19, 2013 and Japanese Application No.2014-020933, filed Feb. 6, 2014, the disclosures of which Applicationsare incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present technique relates to an image processing apparatus, an imageprocessing method, and an imaging apparatus which are capable ofproviding various effects by performing color conversion processing onimage data.

2. Description of the Related Art

Imaging apparatuses use image processing apparatuses configured toperform image processing in accordance with user preference on capturedimage. For example, there has been known an image processing apparatusconfigured to perform color conversion processing (hereinafter, alsoreferred to as one-point color processing) for achromatizing colorsother than a color in a user-specified-region (a color to be remained)on a through image (a live-view image) displayed on a display unitequipped with a touch panel function (for example, see UnexaminedJapanese Patent Publication No. 2012-244337).

SUMMARY OF THE INVENTION

The imaging apparatus according to the present technique has a facedetection unit configured to detect a face region which is determined asa face in an image, a position specifying unit configured to specify aparticular position in the image in response to user operation, a rangespecifying unit configured to set a hue range which has a first rangecontaining a hue at a specified position specified by the positionspecifying unit in a case where the position is not contained in theface region and to set a hue range which has a second range containing ahue at a specified position specified by the position specifying unitand wider than the first range in a case where the position specified bythe position specifying unit contains the face region, and an imageprocessing unit configured to perform image conversion processing basedon color information contained in the hue range set by the rangespecifying unit.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a plan view illustrating a front appearance of a digitalcamera as an example of an imaging apparatus equipped with an imageprocessing apparatus according to an embodiment of the presenttechnique;

FIG. 2 is a plan view illustrating a back appearance of the digitalcamera;

FIG. 3 is a block diagram illustrating a whole configuration of thedigital camera as an example of the imaging apparatus equipped with theimage processing apparatus according to the embodiment of the presenttechnique;

FIG. 4 is a flow chart for describing control of the digital camera in aphotographing mode;

FIG. 5 is an illustration for describing an exemplary state of imagedisplayed on a liquid crystal monitor in a one-point color processingmode in the image processing apparatus of the digital camera accordingto the present technique;

FIG. 6 is an illustration for describing processing on a hue range in acase where a user has specified a position out of a face region of theimage as a position of a color desired to be remained in FIG. 5;

FIG. 7A and FIG. 7B are illustrations for describing processing on a huerange in a case where the user has specified a face region of the imageas a position of a color desired to be remained in FIG. 5; and

FIG. 8 is a flow chart for describing an example of control of one-pointcolor processing in the one-point color processing mode in the imageprocessing apparatus of the digital camera according to the embodimentof the present technique.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Embodiments will be described below with reference to the drawings aboutan image processing apparatus, an image processing method, and animaging apparatus according to the present technique. However,unnecessarily detailed description may be omitted. For example, detaileddescription of already known matters and repetition of substantially thesame configuration may be omitted. Such omissions are for avoidingunnecessary redundancy in the following description to facilitateunderstanding by those skilled in the art.

The applicant provides the accompanying drawings and the followingdescription for those skilled in the art to fully understand the presenttechnique and does not intend to limit the subject described in theclaims by the accompanying drawings and the following description.

1. Configuration

FIG. 1 is a plan view illustrating a front appearance of a digitalcamera as an example of imaging apparatus equipped with an imageprocessing apparatus according to an embodiment of the presenttechnique. FIG. 2 is a plan view illustrating a back appearance of thedigital camera.

A lens barrel accommodating optical system 1 and flash 2 are arranged ona front of a housing of the digital camera. On a top of the housing, anoperation unit including still image release button 3, zoom lever 4, andpower button 5 is arranged. On a back of the housing, liquid crystalmonitor 6 which is a display unit equipped with a touch panel functionfor displaying a through image or a photographed image of a subject isarranged. Further, an operation unit including center button 7,directional button 8, moving image release button 9, and mode switch 10is arranged on the back.

FIG. 3 is a block diagram illustrating a whole configuration of thedigital camera as an example of the imaging apparatus equipped with theimage processing apparatus according to the embodiment of the presenttechnique.

As illustrated in FIG. 3, the digital camera captures a subject imageformed by optical system 1 by using CCD (Charge Coupled Devices) imagesensor 20 which is an imaging unit. CCD image sensor 20 generates imagedata based on the captured subject image. The image data generated byCCD image sensor 20 is sent through AFE (Analog Front End) 21 which is asignal conditioning circuit for adjusting an analog signal to imageprocessing unit 22 which is for performing such processing as imageconversion and is subjected to respective types of image processing. Thegenerated image data is recorded on a data recording unit such as abuilt-in recording medium or a removable external recording medium. Therecording medium may be a flash memory, a memory card, or the like, andit is assumed to be a memory card in the present embodiment.

CCD image sensor 20 captures the subject image formed through opticalsystem 1 and generates the image data. When the digital camera is in aphotographing mode, CCD image sensor 20 can generate a new frame ofimage data for every certain time period.

In AFE 21, noise suppression by correlated double sampling,amplification to an input range width of an A/D converter by an analoggain controller unit, and A/D conversion by the A/D convertor areperformed on the image data read out from CCD image sensor 20.Subsequently, AFE 21 outputs the image data to image processing unit 22.

Image processing unit 22 performs various types of image processing onthe image data output from AFE 21. The various types of image processinginclude smear correction, white balance correction, gamma correction, YCconversion processing, electronic zoom processing, compressionprocessing, and expansion processing. The image processing is notlimited to those types of processing. Image processing unit 22temporarily stores the image information subjected to the various typesof image processing in buffer memory 23. Image processing unit 22performs color conversion processing including one-point colorprocessing on the image data stored in buffer memory 23. The image dataafter the color conversion processing is stored in buffer memory 23.Details of the one-point color processing will be described later.Meanwhile, buffer memory 23 is a storing means functioning as a workmemory for image processing unit 22 or for controller unit 24 and can beimplemented by a DRAM (Dynamic Random Access Memory) or the like.

Controller unit 24 is for controlling the operation of the whole digitalcamera and is implemented by a microcomputer which has a ROM (Read OnlyMemory) for storing programs, a CPU (Central Processing Unit) forprocessing various types of information by executing the programs, andthe like. The ROM stores programs for collectively controlling theoperation of the whole digital camera including file control, autofocuscontrol (AF control), automatic exposure control (AE control), andemission control for flash 2. Controller unit 24 serves as facedetection unit 24A, position specifying unit 24B, and range specifyingunit 24C by executing the programs stored in the ROM.

Face detection unit 24A detects a region determined as a person's facefrom the image data stored in buffer memory 23 to take the region as aface region and stores information of the face region in buffer memory23. Various publicly known techniques can be used as a method fordetecting a region which is a person's face from the image data.

Position specifying unit 24B pinpoints a position or a region in theimage based on user operation and stores it in buffer memory 23 as theposition or the region of a “color desired to be remained”.

Range specifying unit 24C determines a range for calculating anevaluation value and a width of the hue based on the position or theregion of a “color desired to be remained” pinpointed by positionspecifying unit 24B and the face detection result from face detectionunit 24A. Then, range specifying unit 24C determines the range of thecolor desired to be remained as a hue range based on the range forcalculating an evaluation value and the width of the hue. The range forcalculating an evaluation value and the width of the hue will bedescribed in detail later.

Memory card 25 for recording the image data can be attached to/detachedfrom card slot 26 connected to controller unit 24 by the user so that itis electrically and mechanically connected to controller unit 24. Cardslot 26 may be provided with a function of controlling memory card 25.Memory card 25 is an external memory that contains a recording unit suchas a flash memory. Memory card 25 records data such as image data to beprocessed in image processing unit 22. The high pixel count image datato be recorded on memory card 25 is generated by image processing unit22 based on the image data generated by CCD image sensor 20 afterdetection of user operation on the release button. Controller unit 24records on memory card 25 the image data processed in image processingunit 22 and stored in buffer memory 23. The image data recorded onmemory card 25 is displayed on liquid crystal monitor 6 based on useroperation.

Flash memory 27 connected to controller unit 24 functions as an internalmemory for recording the image data and setup information of the digitalcamera. Although flash memory 27 is illustrated to be external tocontroller unit 24 in FIG. 3, it is needless to say that flash memory 27may be contained in controller unit 24.

Optical system 1 includes focus lens 11, zoom lens 12, diaphragm 13, andshutter 14. Focus lens 11 is used for adjusting a focusing state of thesubject. Zoom lens 12 is used for adjusting an angle of view of thesubject. Diaphragm 13 is used for adjusting a light quantity incident onCCD image sensor 20. Shutter 14 adjusts an exposure time of lightincident on CCD image sensor 20. Focus lens 11, zoom lens 12, diaphragm13, and shutter 14 are driven by respectively corresponding drivingmeans such as a DC motor and a stepping motor according to controlsignals sent from controller unit 24. Although not illustrated in thedrawings, optical system 1 may include an Optical Image Stabilizer (OIS)lens. The respective types of lens included in optical system 1 can beimplemented by a plurality of lenses or a plurality of lens groups.

Liquid crystal monitor 6 displays an image based on the image dataprocessed by image processing unit 22. Liquid crystal monitor 6 displaysthe images such as the through image and the recorded image. The throughimage is an image successively displaying a new frame of image datawhich is generated by CCD image sensor 20 for each certain time period.In general, when the digital camera is in the photographing mode, imageprocessing unit 22 generates the through image based on the image datagenerated by CCD image sensor 20. With the through image displayed onliquid crystal monitor 6 for reference, the user can take a photographwhile confirming the composition of the subject. The recorded image ismade as a result of reducing the high pixel count image data recorded onmemory card 25 to low pixel count image data during a playback mode ofthe digital camera.

Operation unit 28 connected to controller unit 24 is for detecting useroperation and collectively refers to operation buttons and switch of thedigital camera described with reference to FIG. 1 and FIG. 2 and a touchpanel installed in liquid crystal monitor 6. When operation unit 28detects user operation, it sends respective operation instructingsignals to controller unit 24. Examples of operation of operation unit28 will be described below.

Still image release button 3 is a two-stage push button which allows ahalf-press operation and a full-press operation. When still imagerelease button 3 is half-pressed by the user, controller unit 24performs AF (Auto Focus) control or AE (Auto Exposure) control todetermine photographing conditions. Subsequently, when still imagerelease button 3 is full-pressed by the user, controller unit 24performs photographing processing. Controller unit 24 records the imagedata captured at a moment of the full-press operation onto memory card25 or the like as a still image. Unless otherwise stated, the expression“to press still image release button 3” is assumed to be correspondingto “to full-press”.

Moving image release button 9 is a push button for instructingstart/finish of moving image recording. When moving image release button9 is pressed by the user, controller unit 24 records the image datagenerated by image processing unit 22 based on the image data generatedby CCD image sensor 20 onto a recording medium such as memory card 25successively as a moving image. When moving image release button 9 ispressed again, the recording of the moving image finishes.

Zoom lever 4 is for adjusting the angle of view between a wide-angle endand a telephoto end inclusive. Zoom lever 4 is implemented by a leverwhich automatically returns to a middle position. When zoom lever 4 isoperated by the user, it sends an operation instructing signal fordriving zoom lens 12 to controller unit 24. In other words, when zoomlever 4 is set to the wide-angle end, controller unit 24 drives zoomlens 12 to capture a wide-angle shot of the subject. Conversely, whenzoom lever 4 is set to the telephoto end, controller unit 24 drives zoomlens 12 to capture a telephoto shot of the subject.

Power button 5 is a push button for the user to instruct the digitalcamera to supply power to the respective components of the digitalcamera. When power button 5 is pressed by the user in the power OFFstate, controller unit 24 supplies power to the respective components ofthe digital camera to activate them. When power button 5 is pressed bythe user in the power ON state, controller unit 24 operates to stopsupplying power to the respective components.

Center button 7 is a push button. When center button 7 is pressed by theuser while the digital camera is in the photographing mode or theplayback mode, controller unit 24 displays a menu screen on liquidcrystal monitor 6. The menu screen is for the user to set respectiveconditions for photography operation/playback operation. The informationset on the menu screen is recorded on flash memory 27. In the case wherethe respective conditional setting items have been selected and centerbutton 7 is pressed, center button 7 functions as a button for decidingon the set conditions.

Directional button 8 is a push button which can be pressed inupward/downward/leftward/rightward directions. By pressing directionalbutton 8 in any one of the directions, the user can select one of therespective conditional items displayed on liquid crystal monitor 6.

Mode switch 10 is a button which can be pressed in upward/downwarddirections. By pressing mode switch 10 in either direction, the user canswitch the state of the digital camera to the photographing mode or theplayback mode.

Image processing unit 22 and controller unit 24 may be implemented byhardwired electronic circuits or may be implemented by a microcomputeror the like which is operated according to programs. Alternatively,image processing unit 22 and controller unit 24 may be formed togetheron a single semiconductor chip. The ROM needs not to be provided insidecontroller unit 24 and may be provided outside of controller unit 24 asan external memory.

An imaging device constituting the imaging unit is not limited to theCCD image sensor and may be another sensor such as a CMOS (ComplementaryMetal-Oxide Semiconductor) image sensor. Further, an imaging unit formedof an optical system, an image sensor, and the like may be implementedby a camera module which has lenses, a CMOS image sensor, part of signalprocessing circuit unit, and the like integrated into a module.

2. Operation

Operation of the digital camera including operation of the imageprocessing apparatus according to the embodiment of the presenttechnique will be described below.

The image processing apparatus in the digital camera of the embodimentcan perform the one-point color processing on captured image data. Thedigital camera displays the image data, and based on the user-specifiedposition of a color desired to be remained and the face detectionresult, determines a range for calculating an evaluation value and a huewidth. Then, the digital camera can determine the color to be remainedbased on the determined range for calculating an evaluation value andthe determined hue width and perform color conversion processing forachromatizing colors other than the color to be remained.

[2-1. Photography Operation of the Digital Camera]

First, the photography operation of the digital camera will bedescribed. FIG. 4 is a flow chart for describing control of the digitalcamera in the photographing mode. The digital camera takes a movingimage and a still image in the photographing mode. Here, the photographyoperation of a still image will be described.

When the digital camera enters the photographing mode in response touser operation performed on mode switch 10, controller unit 24 performsinitialization step S401 for initialization processing necessary torecord a still image.

Next, in mode judgment step S402, controller unit 24 checks the operatedstate of mode switch 10, and in the case where it determines that theswitch is set to the photographing mode (Y), it performs displayprocessing of display step S403 for displaying a through image on liquidcrystal monitor 6 according to current set values. Then, in releasebutton operation judgment step S404, controller unit 24 checks theoperated state of still image release button 3, and in the case where itdetermines that still image release button 3 is pressed and it iscommanded to perform the photography operation (Y), it performsprocessing of photographing step S405 for photographing a still image.Specifically, controller unit 24 records image data of a still imagewhich has been generated by image processing unit 22 based on image datagenerated by CCD image sensor 20 onto a recording medium such as memorycard 25 at the moment when still image release button 3 is pressed.

After performing the processing of still image photographing operationof photographing step S405, controller unit 24 repeatedly performs theprocessing from mode judgment step S402.

On the other hand, in the case where controller unit 24 determines thatthe state of mode switch 10 is not the photographing mode (N) in modejudgment step S402, it finishes the processing without performingoperation of next display step S403. In the case where controller unit24 has not detected depression of still image release button 3, i.e., inthe case where controller unit 24 determines that it is not commanded toperform the photography operation (N) in release button operationjudgment step S404, it repeatedly performs processing from mode judgmentstep S402.

[2-2. Operation of the One-Point Color Processing]

Now, operation of the one-point color processing in the image processingapparatus of the digital camera according to the present technique willbe described.

FIG. 5 is an illustration for describing an exemplary state of imagedisplayed on the liquid crystal monitor in the one-point colorprocessing mode in the image processing apparatus of the digital cameraaccording to the present technique. FIG. 6 is an illustration fordescribing processing on the hue range in the case where the user hasspecified a position out of a face region of the image as a position ofa color desired to be remained in FIG. 5. FIG. 7A and FIG. 7B areillustrations for describing processing on the hue range in the casewhere the user has specified the face region of the image as a positionof a color desired to be remained in FIG. 5.

As illustrated in FIG. 5, in the image processing apparatus of thedigital camera according to the present technique, face detection unit24A of controller unit 24 detects face region 6 a which is determined asa face in the image. Then, position specifying unit 24B specifies aparticular position in the image, for example, a particular positionwhich has a color desired to be remained, based on the user operation.

In the case where range specifying unit 24C determines that position 6 bspecified by position specifying unit 24B is not contained in faceregion 6 a, it sets a default first range (H0±Δh) containing hue H0present at position 6 b specified by position specifying unit 24B as thehue range of a color desired to be remained as illustrated in FIG. 6.

On the other hand, in the case where range specifying unit 24Cdetermines that position 6 c specified by position specifying unit 24Bis contained in face region 6 a, it sets a hue range which has a secondrange (H1±ΔH) containing hue H1 present at position 6 c specified byposition specifying unit 24B and wider than the default first range(H1±Δh) as illustrated in FIG. 7A and FIG. 7B. Since relationshipbetween Δh and ΔH indicating hue ranges is Δh<ΔH in FIG. 7A and FIG. 7B,in the case where position 6 c specified by position specifying unit 24Bis contained in face region 6 a, range specifying unit 24C sets the huerange which has the second range (H1±ΔH) wider than the default firstrange (H1±Δh) as illustrated in FIG. 7A and FIG. 7B as the hue range ofa color desired to be remained.

Although the first range (H1±Δh) is described as the default range inthe description of FIG. 7A and FIG. 7B, it is needless to say that thesecond range (H1±ΔH) may be set as the default range. Further, sincerelationship between the first range and the second range only needs tobe that the second range has a wider hue range than the first rangedoes, the image processing apparatus may be configured to have aplurality of pairs of the first range and the second range in therelationship set in advance for the user to select one from theplurality of pairs of set values.

Further, hue widths Δh and ΔH need not to be added to the both sides ofhues H0 and H1 present at positions specified by position specifyingunit 24B respectively to make the hue ranges of the first range and thesecond range, and the first range and the second range only need tocontain hues H0 and H1 present at the specified positions respectively.For example, in FIG. 7A and FIG. 7B, the first range may be a range withdifferent widths +Δhx and −Δhy added to hue H1 and the second range maybe a range with different widths +ΔHx and −ΔHy added to hue H1. Also inthat case, the relationship between the first range and the second rangeonly needs to satisfy the requirement that the hue width made by +ΔHxand −ΔHy is wider than the hue width made by +Δhx and −Δhy.

Image processing unit 22 performs image conversion processing based oncolor information contained in the hue range set by range specifyingunit 24C of controller unit 24.

As described above, in the image processing apparatus of the digitalcamera according to the present technique, the hue range of a color tobe remained is set wider in the case where the position of a colordesired to be remained is contained in the face region than in the casewhere the position is not contained in the face region. As a result, inthe case where the user has specified the face of a person with theintention of making the color of the whole face of the person remained,the hue range of the color at the specified position, i.e., the skincolor is set rather wide. Therefore, all of various hues of the skincolor contained in the person's face, for example, from a bright hue atthe position where the face is lit to a dark hue at the position wherethe face is shaded from the light are highly possible to be contained inthe color to be remained. Consequently, one-point color processing formaking the color of the whole face of a person remained andachromatizing the other colors becomes available, therefore, one-pointcolor processing nearer to the user's intention becomes available.

FIG. 8 is a flow chart for describing an example of control of theone-point color processing in the one-point color mode in the imageprocessing apparatus of the digital camera according to the embodimentof the present technique.

As illustrated in FIG. 8, first, controller unit 24 determines whetherthe current mode is the one-point color mode or not in mode judgmentstep S501, and in the case where it determines that the current mode isthe one-point color mode (Y), the processing proceeds to the next step,image selection step S502 for selecting an image. In the case wherecontroller unit 24 determines that the current mode is not the one-pointcolor mode (N) in mode judgment step S501, it finishes the processing inthe one-point color mode.

In image selection step S502, controller unit 24 prompts the user toselect image data to be subjected to the one-point color processing.Specifically, controller unit 24 causes liquid crystal monitor 6 todisplay a list of image data recorded on memory card 25. Then, accordingto an operation performed by the user on operation unit 28, controllerunit 24 selects a piece of image data from the list.

Next, in face detection step S503, face detection unit 24A detects aface region in the selected image data. In the case where the image datacontains a region which can be determined as a face of a person, theregion is stored in buffer memory 23 as a set of a center position, alength and a width of the region. Then, controller unit 24 performsdisplay step S504 for displaying an image based on the image data onliquid crystal monitor 6. On that occasion, controller unit 24 causes aframe enclosing face region 6 a to be superimposed on the imagedisplayed on liquid crystal monitor 6 as illustrated in FIG. 5.Meanwhile, the frame enclosing face region 6 a is not limited to besquare as illustrated in FIG. 5 and, further, does not need to bedisplayed.

Subsequently, position specifying unit 24B performs position specifyingstep S505 for prompting the user to select a position in the image forthe user to decide on a color desired to be remained. Specifically, whenthe user operates directional buttons 8 or the like while liquid crystalmonitor 6 is displaying the image, position specifying unit 24B moves acursor on the image based on the user operation. In the case where theuser presses center button 7 when the cursor has moved to a desiredposition, position specifying unit 24B stores the position of the cursorat the moment in buffer memory 23 as the position of a color desired tobe remained. As another example, the image processing apparatus may beconfigured to have a touch panel function added to liquid crystalmonitor 6 so that the user selects the position by directly touching thescreen of liquid crystal monitor 6.

Next, range specifying unit 24C performs face region judgment step S506for judging whether the position of a color desired to be remainedacquired in position specifying step S505 is in the face region detectedin face detection step S503. In the case where range specifying unit 24Cdetermines that the position of a color desired to be remained acquiredin position specifying step S505 is in the face region (Y), it sets therange for calculating the evaluation value smaller than a default value(standard) in range specifying step S507. Further, in range specifyingstep S508, range specifying unit 24C sets the hue range wider than thedefault range as described above.

On the other hand, in the case where range specifying unit 24Cdetermines that the position of a color desired to be remained acquiredin position specifying step S505 is not in the face region (N), it setsthe range for calculating the evaluation value to the default value(standard) in range specifying step S509. Further, in range specifyingstep S510, range specifying unit 24C sets the hue range of the colordesired to be remained to the default first range as described above.

Now, the range for calculating the evaluation value will be described.In finally determining the hue range of the color desired to beremained, the hue which would come to the center (median value) of thehue range is determined as the evaluation value. The evaluation valuecan be calculated as a mean value of hues of surrounding pixels in aparticular region around the user-specified position. The particularregion on that occasion is the range for calculating the evaluationvalue. Specifically, in the case where the range for calculating theevaluation value is rectangular, the range for calculating theevaluation value is set to satisfy expressions X1<X0 and Y1<Y0, where X0is the width and Y0 is the height of a default standard range forcalculating the evaluation value and X1 is the width and Y1 is theheight of the range in the case where it is determined that the positionof a color desired to be remained is in the face region. The hue rangeindicates a color to be remained in the form of a hue range of the coloras a range from the evaluation value around the hue indicated by theevaluation value.

Next, range specifying unit 24C calculates the evaluation value inevaluation value calculation step S511. Specifically, range specifyingunit 24C calculates a mean value of hues of pixels in a range forcalculating the evaluation value which has been set in range specifyingstep S507 or S509 around the position of a color desired to be remainedselected in position specifying step S505, and takes the mean value asthe evaluation value.

Next, range specifying unit 24C determines the hue range as describedabove in hue range setting step S512.

Next, controller unit 24 performs the color conversion processing inimage processing step S513. Specifically, controller unit 24 performsthe color conversion processing by controlling image processing unit 22.Image processing unit 22 takes color information contained in the huerange at the position specified by position specifying unit 24B (the huerange determined in hue range setting step S512) as standard colorinformation and performs the image conversion processing for changingcolor information of a particular region of the image wherein theparticular region of the image has color information which is notcontained in the standard color information. In the case of theone-point color processing, image processing unit 22 performs the imageconversion processing for achromatizing a particular region of the imagewherein the particular region of the image has color information whichis not contained in the standard color information.

The color conversion processing is not performed on pixels which havehues within the hue range. Then, image processing unit 22 performsdisplay step S514 for displaying the image which has been subjected tothe color conversion processing in image processing step S513 on liquidcrystal monitor 6. Finally, image processing unit 22 performs recordstep S515 for recording the image data which has been subjected to theone-point color processing on flash memory 27.

In the above embodiment, although a case of one-point color processingfor achromatizing a particular region in the image has been described asan example of image conversion for changing color information of aparticular region of the image wherein the particular region of theimage has color information which is not contained in the standard colorinformation, the image conversion may be processing for converting thecolor information into a chromatic color such as sepia. Further, imageconversion for changing brightness or contrast of an image may beperformed on the position specified by position specifying unit 24B.Moreover, in converting the color information of a particular regionwhich has color information different from the standard colorinformation, the processing for converting the color information may beperformed also on the position specified by position specifying unit 24Bon the condition that the color information is converted into colorinformation other than the color information of the particular region.

3. Summarization

The digital camera which has the image processing apparatus according tothe present technique has an imaging unit for capturing a subject image,a data recording unit for recording image data generated on the basis ofthe subject image captured by the imaging unit, a display unit fordisplaying an image based on the image data recorded in the datarecording unit, and an image processing apparatus configured to performimage processing on the image displayed on the display unit.

The image processing apparatus has controller unit 24 configured to seta hue range which has a first range containing a hue at a positionspecified by user operation in a case where a particular position in theimage specified by user operation is not contained in the face region ofthe image and to set a hue range which has a second range containing ahue at a position specified by user operation and wider than the firstrange in a case where the specified particular position in the imagespecified by user operation contains the face region.

Controller unit 24 has face detection unit 24A configured to detect aface region which is determined as a face in an image, positionspecifying unit 24B configured to specify a particular position in theimage in response to user operation, and range specifying unit 24Cconfigured to set a hue range which has a first range containing a hueat a position specified by position specifying unit 24B in a case wherethe position specified by position specifying unit 24B is not containedin the face region and to set a hue range which has a second rangecontaining a hue at a position specified by position specifying unit 24Band wider than the first range in a case where the position specified byposition specifying unit 24B contains the face region. Image processingunit 22 of the image processing apparatus performs image conversionprocessing based on color information contained in the hue range set byrange specifying unit 24C of controller unit 24.

With that configuration, the hue range of a color to be remained is setwider in the case where the position of a color desired to be remainedis contained in the face region than in the case where the position isnot contained in the face region. As a result, in the case where theuser has specified the face of a person with the intention of making thecolor of the whole face of the person remained, the hue range of thecolor at the specified position, i.e., the skin color is set ratherwide. Therefore, all of various hues of the skin color contained in theperson's face, for example, from a bright hue at the position where theface is lit to a dark hue at the position where the face is shaded fromthe light are highly possible to be contained in the color to beremained. Consequently, one-point color processing for making the colorof the whole face of a person remained and achromatizing the othercolors becomes available, therefore, one-point color processing nearerto the user's intention becomes available.

4. Other Embodiments

The present technique is not limited to the above described embodiment.Other embodiments of the present technique will be described below.

In the embodiment described in FIG. 8, range specifying unit 24C isconfigured to set both of the range for calculating an evaluation valueand the width of a hue based on whether the position of a color desiredto be remained is contained in the face region or not and to set the huerange of the color desired to be remained based on both of the range forcalculating an evaluation value and the width of a hue. However, therange for calculating an evaluation value may be a fixed default rangeset by the user or the apparatus without regard to whether the positionof a color desired to be remained is contained in the face region ornot.

Further, in the embodiment described in FIG. 8, range specifying unit24C is configured to determine the median value of a hue range of acolor desired to be remained by setting the range for calculating anevaluation value and also to determine the hue range of a color desiredto be remained by setting the width of a hue. However, range specifyingunit 24C may be configured to determine an evaluation value of a huedesired to be remained based on the user-specified position of a colordesired to be remained and to determine the hue range desired to beremained by reading out appropriate data from a table based on theevaluation value and the result of judgment on whether theuser-specified position is contained in the face region or not. Forexample, in the case where the position of a color desired to beremained is contained in the face region, range specifying unit 24C mayset the hue range corresponding to a skin color previously stored inflash memory 27 as the hue range of the color desired to be remained. Onthe other hand, in the case where the position of a color desired to beremained is not contained in the face region, range specifying unit 24Cmay select a hue range based on the evaluation value from among aplurality of hues previously stored in flash memory 27 and set the huerange as the hue range of the color desired to be remained. Also in thatcase, the hue range corresponding to a skin color is set wider in thecase where the position of the color desired to be remained is containedin the face region than a plurality of hue ranges in the case where theposition of the color desired to be remained is not contained in theface region. Range specifying unit 24C may be configured to have thetable for determining a color desired to be remained in a form otherthan a hue table. For example, range specifying unit 24C may beconfigured to have the table of colors desired to be remained in a formof color information represented by RGB color space.

The embodiment has been provided by the accompanying drawings and thedetailed description as described above. The present inventor providesthe accompanying drawings and the detailed description to exemplify thesubject matter defined in the claims with reference to a particularembodiment for those skilled in the art. Therefore, the constituentelements illustrated in the accompanying drawings and described in thedetailed description may include not only a constituent element which isnecessary to solve the problem but also a constituent element which isnot necessary to solve the problem. Accordingly, it should not beinstantly understood that the unnecessary constituent element isnecessary only because the unnecessary constituent element isillustrated in the accompanying drawings or discussed in the detaileddescription. Further, various changes, substitutions, addition and/oromission and the like may be performed on the embodiment within thescope of the claims and the equivalent of the claims.

Since color conversion processing nearer to the user's intention becomesavailable according to the present technique, the technique can be alsoapplied to a digital still camera, a digital video camera, a mobilephone, a smart phone, a mobile PC, and the like.

What is claimed is:
 1. An image processing apparatus comprising: a facedetection unit configured to detect a face region which is determined asa face in an image; a position specifying unit configured to specify aparticular position in the image in response to user operation; a rangespecifying unit configured to set a hue range which has a first rangecontaining a hue at a position specified by the position specifying unitin a case where the position is not contained in the face region and toset a hue range which has a second range containing a hue at a positionspecified by the position specifying unit and wider than the first rangein a case where the position specified by the position specifying unitis contained in the face region; and an image processing unit configuredto perform image conversion processing based on color informationcontained in the hue range set by the range specifying unit.
 2. Theimage processing apparatus according to claim 1, wherein the imageprocessing unit is configured to take color information contained in thehue range at the position specified by the position specifying unit asstandard color information and perform image conversion processing forchanging color information of a particular region of the image, theparticular region of the image having color information which is notcontained in the standard color information.
 3. The image processingapparatus according to claim 1, wherein the image processing unit isconfigured to take color information contained in the hue range at theposition specified by the position specifying unit as standard colorinformation and perform image conversion processing for achromatizing aparticular region of the image, the particular region of the imagehaving color information which is not contained in the standard colorinformation.
 4. An image processing method comprising: detecting a faceregion which is determined as a face in an image; specifying aparticular position in the image in response to user operation; settinga hue range which has a first range containing a hue at a positionspecified by the user operation in a case where the position specifiedby user operation is not contained in the face region and setting a huerange which has a second range containing a hue at a position specifiedby user operation and wider than the first range in a case where theposition specified by user operation is contained in the face region;and performing image conversion processing based on color informationcontained in the hue range.
 5. The image processing method according toclaim 4, further comprising: performing image conversion processing forchanging color information of a particular region of the image, theparticular region of the image having color information which is notcontained in a standard color information, the standard colorinformation being color information contained in the hue range at theposition specified by user operation.
 6. The image processing methodaccording to claim 4, further comprising: performing image conversionprocessing for achromatizing a particular region of the image, theparticular region of the image having color information which is notcontained in the standard color information, the standard colorinformation being color information contained in the hue range at theposition specified by user operation.
 7. An imaging apparatuscomprising: an imaging unit for capturing a subject image; a datarecording unit for recording image data generated based on the subjectimage captured by the imaging unit; a display unit for displaying animage based on the image data recorded in the data recording unit; andan image processing apparatus configured to perform image processing onthe image displayed on the display unit, wherein the image processingapparatus comprises: a controller unit configured to set a hue rangewhich has a first range containing a hue at a position specified by useroperation in a case where a particular position in the image specifiedby user operation is not contained in a face region of the image and toset a hue range which has a second range containing a hue at a positionspecified by user operation and wider than the first range in a casewhere a particular position in the image specified by user operation iscontained in the face region; and an image processing unit configured toperform image conversion processing based on color information containedin the hue range set by the controller unit.
 8. The imaging apparatusaccording to claim 7, wherein the image processing unit is configured totake color information contained in the hue range at the positionspecified by user operation as standard color information and performimage conversion processing for changing color information of aparticular region of the image, the particular region of the imagehaving color information which is not contained in the standard colorinformation.
 9. The imaging apparatus according to claim 7, wherein theimage processing unit is configured to take color information containedin the hue range at the position specified by user operation as standardcolor information and perform image conversion processing forachromatizing a particular region of the image, the particular region ofthe image having color information which is not contained in thestandard color information.